The present invention relates to a light-emitting device, a light-emitting apparatus, an image display apparatus, a method of manufacturing a light-emitting device, and a method of manufacturing an image display apparatus. More particularly, the present invention relates to a light-emitting device, a light-emitting apparatus, an image display apparatus, a method of manufacturing a light-emitting device, and a method of manufacturing an image display apparatus in which light emission efficiency is prevented from being lowered and an electrode is formed for minute light-emitting device main bodies with high accuracy.
At present, in electronic apparatuses and the like, there have been widely used those configured by arranging a multiplicity of minute devices, electronic component parts, electronic devices, and electronic component parts obtained by embedding these in an insulator such as a resin. For example, in the case of assembling an image display apparatus by arranging light-emitting devices in a matrix form, conventionally, there has been practiced a method of forming the devices directly on a substrate as in the cases of a Liquid Crystal Display apparatus (LCD) and a Plasma Display Panel (PDP) or a method of arranging single Light-Emitting Diode (LED) packages as in the case of an LED display.
Besides, since LEDs as light-emitting devices are expensive, an image display apparatus using the LEDs can be manufactured at low cost by manufacturing a large number of LED chips from one sheet of wafer. Namely, when the LEDs are miniaturized from the conventional size of about 300 μm square to a size of several tens of micrometers square and are connected to produce an image display apparatus, it is possible to lower the price of the image display apparatus. An electrode for such a minute light-emitting device is in many cases produced by a method in which a metallic film is formed as the electrode at a part of a light output surface of a light-emitting device main body, and the electrode is connected to a wiring through a metallic film or a gold wire.
On the other hand, the light-emitting device is electrically connected to a wiring for driving the light-emitting device, and emits light from a predetermined light emission region to the exterior of the device. Therefore, it is important to prevent the light output efficiency from being lowered, by ensuring that the light emitted from the light emission region to the exterior of the device is not shielded by the wiring and/or the electrode formed in the light emission region. In view of this, for example, in relation to light-emitting devices such as a planar light-emitting thyristor and an organic EL device, there has been known a technology of forming a transparent electrode so as not to shield the light emitted from the light emission region (see, for example, Japanese Patent Laid-open No. Hei 9-283801, and Japanese Patent Laid-open No. 2002-260843).
However, it is difficult to form an electrode accurately at the light output surface in a minute light-emitting device. For example, in the case of forming an electrode for a minute light-emitting device main body in which the size of the light output surface is about 10 μm square or below, an accuracy of within about 10 μm is needed for alignment between the light output surface and the electrode. Besides, even in the case where an electrode is formed at the light output surface by use of a light-transmitting material so as not to lower the light output efficiency, also, the formation of the electrode accurately at the light output surface becomes more difficult as the size of the light-emitting device becomes smaller. Furthermore, as the size of the light-emitting device is reduced, the connection between the electrode and the light-emitting device main body would become insufficient, possibly leading to a trouble in driving the light-emitting device.